Senior Mobile App Development Engineer (iOS)

Job Title: Senior Mobile App Development Engineer (iOS) Experience: 5+ Years Location: Remote Contract duration: 3-6 Months Shift timings: Vietnam business hours (9:00 AM – 6:00 PM)

We are seeking an experienced Senior Mobile App Development Engineer (iOS) to join our team and lead the development of advanced smartphone-based digital biomarker capture solutions. This role focuses on owning and optimizing the low-level iPhone sensor capture stack to enable consistent, high-quality facial, ocular, and motion signal acquisition.

Role Summary

The engineer will work at the intersection of Apple frameworks, device-specific constraints, and real-time performance tuning. You will be responsible for building robust, privacy-forward, and high-performance capture workflows that support diagnostic-style smartphone measurements.

Key Responsibilities

Implement and optimize sensor capture flows using TrueDepth, ARKit, AVFoundation, and CoreMotion. Translate algorithm and product requirements into reliable on-device data collection and frame synchronization. Design and build quality-control UX and capture-state instrumentation, including lighting checks, face alignment, motion thresholds, occlusion detection, and retake prompts. Optimize latency, thermal performance, and battery usage for short diagnostic capture sessions (approximately 10 seconds). Ensure privacy-first data handling with data minimization and compliant telemetry. Produce clear, Apple-facing technical documentation explaining API choices and data handling approaches.

Expected Deliverables

A modular capture SDK layer with feature flags and comprehensive logging. Cross-device performance benchmarking matrix and tuning guidelines. Deterministic quality-control gates that reduce noise in biometric outputs.

Required Skills and Experience

5+ years of hands-on iOS engineering experience with deep expertise in sensor and camera frameworks. Strong experience with ARKit face tracking, blendshapes, eye metrics, and depth-enabled workflows. Advanced performance profiling skills using Instruments, including memory, thermal, and performance audits. Ability to write clear, well-reasoned technical justifications aligned with product and risk requirements.

Nice to Have

Experience working on health or health-adjacent consumer applications using camera-based vital measurements. Familiarity with on-device machine learning (Core ML) and mobile privacy architectures.